. >> congresswoman gabrielle gifford was seriously injured by gun violence was by the president cited quotas being. the measure did not pass. she accused the opposing senators of cowardice. the final vote tally 54 to 46. the probe was part of a compromise struck by democratic and republican senator. the filibuster requires 60 votes. the bill backed by president obama called face fierce opposition from the national rifle association. a ban on assault weapons also failed along with a bid to block the sale of high capacity ammunition clips. >> new details on the ricin letter sent to president obama. as an official says the lab tests confirmed the letter's into mississippi senator roger wicker did contain the deadly substance rycin . and that more tests are expected. meantime, an arrest is made in the case. federal agents arrested 45 year-old paul kevin curtis of mississippi. he is now being charged with threatening the life of the president. the senators' letter, along with the president's letter, were both postmarked memphis, tenn. april 8th. but were intercepted at screening facilities